Add an analyzer that triggers a build warning or error if IInvocation.Proceed() is called in an async method

[drauch]

Calling IInvocation.Proceed in an async method is almost always wrong, right? If you are in an async method you are obliged to call IInvocation.CaptureProceedInfo and then call proceedInfo.Invoke instead. An analyzer would have helped us a lot and had spared us lots of debugging time.

Best regards,
D.R.

[stakx]

Code analyzers steering users in the right direction would of course be nice to have. Until then, I'll refer you to our documentation about async interception.